Determine the truth value (true or false) for the following congruence relations: (a) 15 = 3 (mod 6) (b) 6 = 11 (mod 5) (select the correct answer) ○ (a) is true and (b) is false ○ (a) is false and (b) is true ○ (a) is true and (b) is true ○ (a) is false and (b) is false